Disallow invalid use of library names as type names.

Changelog.md

@@ -19,6 +19,7 @@ Bugfixes:
  * Code generator: Fix internal compiler error when referencing members via module name but not using the reference.
  * Code generator: Fix ``ABIEncoderV2`` pragma from the current module affecting inherited functions and applied modifiers.
  * Code generator: Use revert instead of invalid opcode for out-of-bounds array index access in getter.
+ * Type Checker: Disallow invalid use of library names as type name.
  * Type Checker: Fix internal compiler error caused by storage parameters with nested mappings in libraries.
  * Name Resolver: Fix shadowing/same-name warnings for later declarations.
  * Contract Level Checker: Add missing check against inheriting functions with ABIEncoderV2 return types in ABIEncoderV1 contracts.

libsolidity/analysis/DeclarationTypeChecker.cpp

@@ -145,7 +145,11 @@ void DeclarationTypeChecker::endVisit(UserDefinedTypeName const& _typeName)
 	else if (EnumDefinition const* enumDef = dynamic_cast<EnumDefinition const*>(declaration))
 		_typeName.annotation().type = TypeProvider::enumType(*enumDef);
 	else if (ContractDefinition const* contract = dynamic_cast<ContractDefinition const*>(declaration))
+	{
+		if (contract->isLibrary())
+			m_errorReporter.typeError(1130_error, _typeName.location(), "Invalid use of a library name.");
 		_typeName.annotation().type = TypeProvider::contract(*contract);
+	}
 	else
 	{
 		_typeName.annotation().type = TypeProvider::emptyTuple();
@@ -201,23 +205,19 @@ void DeclarationTypeChecker::endVisit(Mapping const& _mapping)
 		return;
 
 	if (auto const* typeName = dynamic_cast<UserDefinedTypeName const*>(&_mapping.keyType()))
-	{
-		if (auto const* contractType = dynamic_cast<ContractType const*>(typeName->annotation().type))
+		switch (typeName->annotation().type->category())
 		{
-			if (contractType->contractDefinition().isLibrary())
+			case Type::Category::Enum:
+			case Type::Category::Contract:
+				break;
+			default:
 				m_errorReporter.fatalTypeError(
-					1665_error,
+					7804_error,
 					typeName->location(),
-					"Library types cannot be used as mapping keys."
+					"Only elementary types, contract types or enums are allowed as mapping keys."
 				);
+				break;
 		}
-		else if (typeName->annotation().type->category() != Type::Category::Enum)
-			m_errorReporter.fatalTypeError(
-				7804_error,
-				typeName->location(),
-				"Only elementary types, contract types or enums are allowed as mapping keys."
-			);
-	}
 	else
 		solAssert(dynamic_cast<ElementaryTypeName const*>(&_mapping.keyType()), "");
 
@@ -243,6 +243,7 @@ void DeclarationTypeChecker::endVisit(ArrayTypeName const& _typeName)
 		solAssert(!m_errorReporter.errors().empty(), "");
 		return;
 	}
+
 	solAssert(baseType->storageBytes() != 0, "Illegal base type of storage size zero for array.");
 	if (Expression const* length = _typeName.length())
 	{
@@ -393,13 +394,36 @@ void DeclarationTypeChecker::endVisit(VariableDeclaration const& _variable)
 
 }
 
-void DeclarationTypeChecker::endVisit(UsingForDirective const& _usingFor)
+bool DeclarationTypeChecker::visit(UsingForDirective const& _usingFor)
 {
 	ContractDefinition const* library = dynamic_cast<ContractDefinition const*>(
 		_usingFor.libraryName().annotation().referencedDeclaration
 	);
+
 	if (!library || !library->isLibrary())
 		m_errorReporter.fatalTypeError(4357_error, _usingFor.libraryName().location(), "Library name expected.");
+
+	_usingFor.libraryName().annotation().type = TypeProvider::contract(*library);
+	if (_usingFor.typeName())
+		_usingFor.typeName()->accept(*this);
+
+	return false;
+}
+
+bool DeclarationTypeChecker::visit(InheritanceSpecifier const& _inheritanceSpecifier)
+{
+	auto const* contract = dynamic_cast<ContractDefinition const*>(_inheritanceSpecifier.name().annotation().referencedDeclaration);
+	solAssert(contract, "");
+	if (contract->isLibrary())
+	{
+		m_errorReporter.typeError(
+			2571_error,
+			_inheritanceSpecifier.name().location(),
+			"Libraries cannot be inherited from."
+		);
+		return false;
+	}
+	return true;
 }
 
 bool DeclarationTypeChecker::check(ASTNode const& _node)

libsolidity/analysis/DeclarationTypeChecker.h

@@ -59,7 +59,8 @@ private:
 	void endVisit(ArrayTypeName const& _typeName) override;
 	void endVisit(VariableDeclaration const& _variable) override;
 	bool visit(StructDefinition const& _struct) override;
-	void endVisit(UsingForDirective const& _usingForDirective) override;
+	bool visit(UsingForDirective const& _usingForDirective) override;
+	bool visit(InheritanceSpecifier const& _inheritanceSpecifier) override;
 
 	langutil::ErrorReporter& m_errorReporter;
 	langutil::EVMVersion m_evmVersion;

libsolidity/analysis/TypeChecker.cpp

@@ -276,9 +276,6 @@ void TypeChecker::endVisit(InheritanceSpecifier const& _inheritance)
 	if (m_currentContract->isInterface() && !base->isInterface())
 		m_errorReporter.typeError(6536_error, _inheritance.location(), "Interfaces can only inherit from other interfaces.");
 
-	if (base->isLibrary())
-		m_errorReporter.typeError(2571_error, _inheritance.location(), "Libraries cannot be inherited from.");
-
 	auto const& arguments = _inheritance.arguments();
 	TypePointers parameterTypes;
 	if (!base->isInterface())
@@ -508,9 +505,6 @@ bool TypeChecker::visit(VariableDeclaration const& _variable)
 	TypePointer varType = _variable.annotation().type;
 	solAssert(!!varType, "Variable type not provided.");
 
-	if (auto contractType = dynamic_cast<ContractType const*>(varType))
-		if (contractType->contractDefinition().isLibrary())
-			m_errorReporter.typeError(1273_error, _variable.location(), "The type of a variable cannot be a library.");
 	if (_variable.value())
 	{
 		if (_variable.isStateVariable() && varType->containsNestedMapping())

test/libsolidity/syntaxTests/array/invalid/library_array.sol

@@ -0,0 +1,8 @@
+library L {}
+contract C {
+	function f() public {
+		L[] memory x;
+	}
+}
+// ----
+// TypeError 1130: (51-52): Invalid use of a library name.

test/libsolidity/syntaxTests/array/library_array.sol

@@ -0,0 +1,8 @@
+library L {}
+contract C {
+  function f() public pure {
+    new L[](2);
+  }
+}
+// ----
+// TypeError 1130: (63-64): Invalid use of a library name.

test/libsolidity/syntaxTests/bound/using_for_library.sol

@@ -0,0 +1,11 @@
+library L {}
+library M {}
+contract C {
+    using L for M;
+    using M for L;
+    using L for L;
+}
+// ----
+// TypeError 1130: (55-56): Invalid use of a library name.
+// TypeError 1130: (74-75): Invalid use of a library name.
+// TypeError 1130: (93-94): Invalid use of a library name.

test/libsolidity/syntaxTests/functionCalls/new_library.sol

@@ -0,0 +1,8 @@
+library L {}
+contract C {
+  function f() public pure {
+    new L();
+  }
+}
+// ----
+// TypeError 1130: (63-64): Invalid use of a library name.

test/libsolidity/syntaxTests/inheritance/override/override_library.sol

@@ -0,0 +1,6 @@
+library L {}
+contract C {
+	function f() public override (L) {}
+}
+// ----
+// TypeError 1130: (57-58): Invalid use of a library name.

test/libsolidity/syntaxTests/nameAndTypeResolution/301_library_instances_cannot_be_used.sol

@@ -6,5 +6,4 @@ contract test {
     }
 }
 // ----
-// TypeError 1273: (87-90): The type of a variable cannot be a library.
-// TypeError 9582: (100-103): Member "l" not found or not visible after argument-dependent lookup in library L.
+// TypeError 1130: (87-88): Invalid use of a library name.

test/libsolidity/syntaxTests/nameAndTypeResolution/524_accept_library_creation.sol

@@ -1,6 +0,0 @@
-library L {}
-contract C {
-    function f() public {
-        new L();
-    }
-}

test/libsolidity/syntaxTests/nameAndTypeResolution/typeChecking/library_instances.sol

@@ -9,6 +9,6 @@ contract Y {
 	}
 }
 // ----
-// TypeError 1273: (29-34): The type of a variable cannot be a library.
-// TypeError 1273: (50-57): The type of a variable cannot be a library.
-// TypeError 1273: (77-82): The type of a variable cannot be a library.
+// TypeError 1130: (29-30): Invalid use of a library name.
+// TypeError 1130: (50-51): Invalid use of a library name.
+// TypeError 1130: (77-78): Invalid use of a library name.

test/libsolidity/syntaxTests/types/mapping/library_mapping.sol

@@ -1,4 +1,9 @@
 library L {}
-contract C { mapping(L => bool) i; }
+contract C
+{
+  mapping(bool => L) j;
+  mapping(L => bool) i;
+}
 // ----
-// TypeError 1665: (34-35): Library types cannot be used as mapping keys.
+// TypeError 1130: (44-45): Invalid use of a library name.
+// TypeError 1130: (60-61): Invalid use of a library name.